01/03/2026
41 Earthquake in 18 Days, is it shaking the Building or Confidence?
This question has been on my mind throughout this month. Every earthquake tremor felt was not just a movement of the earth beneath us rather it was also a subtle movement inside us. A reminder that we live in a seismic region. A reminder that safety is not a feeling; it is an engineering outcome. Today I want to write something that is both personal and professional. It is about the frequent earthquakes we have been experiencing this month. If you are a house owner, if you are planning to build a house/structure in the near future, or if the safety of your house sometimes worry you, and if you are a Civil Engineer then this is something you should read very carefully.
With the revision of earthquake design philosophy from IS 1893:2016 to IS 1893:2025 and the inclusion of Sikkim into Zone VI, it became clear that our region is considered highly vulnerable to seismic activity. But before February, nothing felt different. Life was normal. Everything seemed stable. Almost “green as chlorophyll.” Then came February when 41 earthquakes were recorded in just 18 days. As per the National Center for Seismology (Government of India), the M 4.5 earthquake of 6th February 2026 occurred at a shallow depth of 10 km near the Tista Fault/Lineament and was followed by at least 12 aftershocks within 4 hours and 30 minutes. The maximum reported intensity reached VI on the Modified Mercalli Intensity (MMI) scale in the epicentral region. The recorded Peak Ground Acceleration (PGA) at Gangtok was 0.0032g. These are not random tremors they are scientifically recorded seismic responses of an active tectonic zone where the Indian Plate subducts beneath the Eurasian Plate. Yes February month validated the code revision. The warnings were not theoretical. They were real and the uncomfortable truth is that many structures in Sikkim have been built based on “logic” rather than numerical structural proof. Sometimes this happens because of lack of skilled professionals, sometimes due to cost concerns, and sometimes simply due to overconfidence in experience. But logic always comes with probability and probability, when human life and property are involved, is a risky gamble.
When an earthquake occurs, the ground undergoes acceleration (Peak Ground Acceleration – PGA). The foundation moves along with the soil, but the superstructure (beams, columns, slabs etc.) resists this motion due to inertia. This resistance generates inertial forces proportional to the mass of the building and the ground acceleration. As a result, relative displacement develops between the foundation and the upper structure, causing the building to vibrate back and forth. This vibration is what we feel as shaking. In reality, that shaking is your building trying to survive. It is resisting collapse. During this entire process of loading, deflection, and vibration, the most critical elements are the structural components i.e. columns, beams, slabs, tie beams, RCC walls, shear walls, and footings. These are the backbone of your building. They are the elements that determine whether your structure will stand strong after an earthquake. If these elements develop cracks, we must pay attention. Though not all cracks are dangerous. Minor cracks in partition walls (non-structural walls) are usually not a major concern. But if cracks appear in structural members, if they follow a pattern, if they occur near joints, or if they appear randomly and increase over time, then we need to be vigilant. Buildings communicate through symptoms. We need to understand those symptoms with engineering precision, not assumption.
The most crucial decision comes when we talk about repairing structural damage. Repairing a structural member is not just patchwork, you should not just repeat the same mistake of “ASSUMPTION” and “LOGIC” based construction/repair. It is not simply mixing cement, sand, chemicals and applying it over a crack. It is not about adding a few extra rebars or increasing the size of a column blindly. Structural repair means rebuilding the muscle of the building. It requires proper technical evaluation to understand the extent of damage, the load path, the feasibility of restoration, and the durability of the intervention. Without engineering assessment, repairs may become cosmetic instead of structural.
Before you scroll past this post, ask yourself honestly:
• Was my house designed using proper structural calculations or just assumption/experience?
• If a stronger earthquake strikes tomorrow, am I confident my building can resist it?
• Do I really know the difference between a harmless plaster crack and a structural crack?
• Has my building ever been technically evaluated after recent tremors?
• Am I waiting for visible damage before taking action?
Sometimes awareness is the first step toward safety.
If you ever feel uncertain about the health of your building, if your structure is aged, or if you want to know whether it needs strengthening to perform better during earthquakes, do not ignore that instinct. Seeking expert advice is not panic rather it is a responsibility.
At BALKAPSO Construction, we have completed over 150 structural assessment, design and retrofitting projects. Because our team has grown up in this terrain. We understand how ground shaking affects our people, not just structurally, but financially and psychologically.
If you feel the need for expert consultation, you can reach us on WhatsApp at +91 70762 19337.
When it comes to structural safety, trust is what we build well. And in these uncertain times, know that BALKAPSO has got your back.
